System for programmed control of signal input and output to and from cable conductors

ABSTRACT

An input/output module for implementing directions from a controller for sending and receiving signals to and from devices. The input/output module includes a microprocessor for communication with, and receiving programming from the controller. The input/output module further includes device communication connectors, each having number of pins, each pin for interconnection with a cable conductor to a device. The input/output module has an ASIC for each of the pins, providing a controlled interface with the corresponding pin. Each ASIC has interconnection apparatus, selectable by the microprocessor for providing a particular interface with the pin served by the ASIC.

This application is a continuation of U.S. patent application Ser. No.11/296,134 filed Dec. 6, 2005, which is a continuation-in-part of U.S.patent application Ser. No. 11/043,296 filed Jan. 25, 2005 (nowabandoned), which is a continuation-in-part of U.S. patent applicationSer. No. 10/071,870 filed Feb. 8, 2002 (now U.S. Pat. No. 6,892,265),which claims the benefit of U.S. Provisional Application Ser. No.60/269,129 filed Feb. 14, 2001. The foregoing disclosures areincorporated herein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to cabling and cabling systems,and more particularly to a universal cabling system wherein therequirement for specific wire interconnections between first and seconddevices is accomplished through use of a programmable I/O module formaking connection to the first device, and directing connections fromthe first device to selected wires of a cable for connection to thesecond device.

2. Description of the Prior Art

Complex electrical/electronic systems often require custom cableconfigurations. Cables are usually special configurations for aparticular application. Even in relatively simple systems such as homeaudio and small computer systems, a number of different cables aretypically required. In larger applications, such as industrial controlsystems, the number of custom cable designs is extensive. In industrialcontrol systems such as those that run automotive plants, etc.,interaction is required between control apparatus and sensors andactuators. The apparatus providing the corresponding connections will bereferred to as input and output systems. Through the output system, thecontrol system can turn on lights, pumps, valves and other devices.Similarly, through the input system, the control system can sense thestate of a pushbutton, whether a switch is on or off, or whether a tankis full or how fast a shaft is turning.

In prior art control systems, such as a Programmable Logic Controller(PLC), the user of the control system electrically connects the sensorsand actuators to the input/output systems using individual wireconnections or via connectorized wire harnesses. A common method ofconnecting sensors and actuators to industrial control systems isthrough the use of individual wire connections via terminal blocks.Terminal blocks usually employ a screw-driven clamp. An electricalwire's insulation is removed from the end, and then the bare wire isslid under the screw-driven clamp. The screw is then tightened to securethe wire under the clamp and effect an electrical connection between thewire and the terminal block. Increasingly, various spring clamps areused to hold the wire, but these are essentially the same asscrew-driven clamps. FIG. 1 shows how individual wires 10 are connectedto the input and output Modules 12, 14 of a PLC 16 through terminalblocks 18 to three devices, a light bulb 20, a switch 22 and a proximityswitch 24. A proximity switch is a common type of switch that can detectthe presence (typically) of metal, and gives an indication byinterrupting or passing electrical current.

A disadvantage of the method illustrated in FIG. 1 is that the terminals26, 28 on the input or output modules of the PLC 16 are not necessarilyconveniently arranged for facilitating easy connection of a load, suchas a light bulb or switch. As a result, a great deal of custom,hand-wiring must be performed in order to effect the interconnections.In addition the electricity, from a supply 30 to power certain actuatorsand sensors such as the light bulb or proximity sensor, must be providedon the terminal blocks 18 in order to make connections to the light bulbor switch. In general, the prior art output Modules 12 and 14 do notsupply power to the load, they only switch the power. The custom wiringdesign and implementation illustrated in FIG. 1 significantly adds tothe cost and size of the system.

Another method of connecting an industrial control system such as a PLCto a load is via a connectorized wire harness or cable. FIG. 2 shows oneinput module 32 and one output module 34 from a PLC 36. The input/outputmodules 32 and 34 are equipped with connectors 38 and 40 respectivelythat allow cables 42 and 44 to be used to make connection with varioussensors and actuators. Unfortunately, the cable from the input or outputmodule cannot generally connect directly to the sensor or actuatorbecause the connectors 38 and 40 on the PLC 36 are rarely configured toaccept a sensor signal or provide the actuator power. For this reason,FIG. 3 represents the most common method of connecting a PLC to a sensoror actuator when employing connectors on the PLC. In FIG. 3, cables 40from the PLC input 32 and output 34 modules connect to circuit boards 46and 48 which contain terminal blocks 50 for making connections to thecontrol system. Therefore, even when connectorized cables are employed,the prior art still requires making connections through use ofindividual wire connections such as terminal blocks.

Making a direct connection between a PLC and a sensor or actuatorwithout individual wire connections is problematical. An examplesituation is when a PLC must be connected to a device that already isequipped with a connector. The need to connect a PLC to such a device isvery common. A typical device is a mass flow controller equipped with aconnector for connecting signals that must be connected to the PLC. Inthis case, the connections are complicated by the fact that the PLCoutput module contains only outputs and the PLC input module containsonly inputs, whereas the mass flow controller connector contains signalsthat represent both inputs and outputs. To make matters worse, some ofthe signals are discrete—that is, on/off—and some are continuouslyvarying analog signals. In addition, the mass flow controller alsorequires application of a power supply voltage and return/ground to theflow controller connector.

In general, prior art methods and apparatus require the use of customcable harnesses designed and built to connect the rigid format of a PLCto the varying formats of the disparate devices such as mass flowcontrollers and power supplies. The difficulty of designing, fabricatingand installing complex wire harnesses is so great that the predominantmethod of connecting PLC's to sensors and actuators is via individualwire connections and terminal blocks.

FIGS. 4 a and 4 b show two examples of typical non-standard cableconstruction. In FIG. 4 a each of wires 52 and 54 connects to adifferent pin on connector 56 than on connector 58. The cable of FIG. 4b has two connectors 60 and 62 on one end and a single connector 64 onthe other end.

SUMMARY

It is therefore an object of the present invention to provide a methodand apparatus wherein customized connections can be made using standardcables.

It is another object of the present invention to provide a method andapparatus that reduces the cable complexity involved in makinginterconnections in control systems.

It is a further object of the present invention to provide a method andapparatus for reducing the number of custom designed cables andindividual wire connections in a system.

It is an object of the present invention to provide a programmableinput/output module for directing signals between apparatus throughstandard cables.

It is another object of the present invention to provide an improvedsystem for testing cables utilizing programmable input/output modules.

It is a still further object of the present invention to provide aninterlock system for a control system that uses programmableinput/output modules and standard cables.

Briefly, a preferred embodiment of the present invention includes aninput/output module for implementing directions from a controller forsending and receiving signals to and from devices. The input/outputmodule includes a microprocessor for communication with, and receivingprogramming from the controller. The input/output module furtherincludes device communication connectors, each having a number of pins,each pin for interconnection with a cable conductor to a device. Theinput/output module has an application specific integrated circuit(ASIC) for each of the pins, providing a controlled interface with thecorresponding pin. Each ASIC has a plurality of interconnectionapparatus, each apparatus selectable by the microprocessor for providinga particular interface with the pin served by the particular ASIC. Forexample, an interconnection apparatus may provide connection of a powersupply to the pin, another may provide for a particular type of signalto or from a pin.

An advantage of the present invention is that it minimizes or eliminateshand wired interconnections.

A further advantage of the present invention is that it reduces the costof hand wiring, including related documentation, wire stripping, wirelabeling, installation and testing.

A still further advantage of the present invention is that it eliminatesor minimizes the need for custom cable harnesses.

Another advantage of the present invention is that it reduces the timerequired to design a new system.

An advantage of the present invention is that it reduces the quantity ofpart numbers in a system.

A further advantage of the present invention is that it simplifiesmaintaining systems in the field because a smaller number of cables needto be available to replace damaged or suspected cables.

A still further advantage of the present invention is that it aids inmaking system design changes, because new cable designs are generallynot required.

IN THE DRAWING

FIG. 1 illustrates a prior art interconnection system using individualwires;

FIG. 2 illustrates a prior art interconnection system using cables;

FIG. 3 illustrates the prior art use of circuit boards forinterconnecting cable wiring to selected devices;

FIG. 4 a shows a typical prior art custom cable arrangement;

FIG. 4 b shows another typical prior art custom cable arrangement;

FIG. 5 is a block diagram for illustrating the apparatus and method ofthe present invention;

FIG. 6 is a circuit diagram for illustrating further detail of themodule of the connectorized configurable system of the presentinvention;

FIG. 7 is a block diagram illustrating a system for testing cables usingthe module of the present invention;

FIG. 8 is a diagram of a prior art interlock system;

FIG. 9 is a block diagram of an interlock system using the configurableconnectorized input/output module of the present invention;

FIG. 10 illustrates the use of ASIC construction containing elements ofthe system of the present invention; and

FIG. 11 is a more detailed circuit of an example of a pin driverinterface apparatus according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now to FIG. 5 of the drawing, a block diagram is presented forillustration of the method and apparatus of a preferred embodiment ofthe present invention. The apparatus of the present invention includes aconfigurable input/output system 65 including an input/output module 66and one or more cables 68. All of the cables 68 are preferablyidentical, but the present invention also includes variations in thecables 68. Each cable 68 includes one or more conductors and connectors69 and 71. The I/O module 66 according to the present invention includesa microprocessor that is programmable for enabling a particulartransmission of a signal between the module 66 and devices 70, andbetween the module 66 and a system controller 72. The module 66 alsopreferably includes one or more device communication connectors 74,preferably of standard manufacture, for connection to the devicecommunication cables 68, also preferably of standard manufacture. Acontroller communication connector 76 provides connection to a network(preferably Ethernet) 78 for communication between the module 66 and thesystem controller 72. The module 66 is programmed/configured by inputfrom the system controller 72. Alternatively, the module 66 can beconfigured to be programmed through use of a separate computer (notshown).

For example, the module 66 may be programmed to connect a power supplyvoltage from either an external device such as an external supply 79 orfrom a supply built into the module 66, to any one or more of wiresassociated with corresponding cables 68 for transmission tocorresponding interconnected devices 70. As another example, thecontroller 72 may program the module 66 to receive or send a signal fromor to any pin of connector 74.

The module 66 may be programmed to enable transfer of communication databetween any one of the devices 70 and the controller 72, and this mayinvolve any required analog to digital (A/D) or digital to analog (D/A)conversion by the module 66.

FIG. 6 will now be referred to for illustration of further details ofthe I/O module 66. The use of the term “standard” as used in the presentspecification includes any connector and/or cable that is not selectedor designed for a particular connection. The term “standard”, in otherwords is used to distinguish the feature of the present invention thatenables the user to direct input to any one of the conductors of a cablewithout the need to design a special connector or cable wireconfiguration. The term “standard” as used in this sense may or may notinclude an “off-the-shelf” connector or cable that may be designed forany of various purposes. Nevertheless, it is a preferred embodiment ofthe present invention for the method and apparatus to include “standard”connectors and cables in the conventional sense, making wiring lesscostly, and parts more available.

The I/O module 66 as illustrated in FIG. 6 includes a directingapparatus 115 including a microprocessor 82 and alternatively a powersupply 84, and one or more interface apparatus 97. Each interfaceapparatus 97 connects to one line 94 connected to one pin of a connector114. The power supply 84 can alternatively be externally located withinterconnection to I/O module 66 as described in reference to FIG. 5. Aninput line 86 and output line 88 are both shown as required forcommunications input and output respectively, such as Ethernet, betweenthe module 66 and controller 72 according to a preferred embodiment.Other types of interconnections are also included in the presentinvention according to the type of communications network in use. Bus 86of FIG. 6 represents the connection apparatus required for networkcommunications between a controller such as controller 72 of FIG. 5 andthe I/O module 66. Bus 88 of FIG. 6 represents the connection apparatusrequired for communication to another I/O module, such as 124 in FIG. 7between I/O Modules 120 and 122. In general, the microprocessor 82 isconfigured/programmed by a controller 72 to receive instruction from thecontroller as required to sense a particular selected one of devices 96,which may be for example a pressure sensor, temperature sensor, etc.,and provide the corresponding data to the system controller. Themicroprocessor 82 is also programmed/directed by the controller 72 tocause a particular signal to be applied to any selected one or more ofpins on connectors 114 and thereby corresponding conductors of one ormore of the cables 94. In addition, the microprocessor is programmed torespond to direction to send a selected signal type from a device 96 tothe system controller 72.

FIG. 6 shows an interface apparatus 97A, which may contain any number ofinterconnection apparatus such as 98-112, each for providing aparticular selectable interface on a line 94A to a particular pin of aconnector 114A. FIG. 6 shows a second interface apparatus 97B, which canbe identical to apparatus 97A and which connects to another pin of theconnector 114A shown. Similarly an interface apparatus 97 can beprovided for each pin of a connector such as 114A. FIG. 6 then showsanother connector 114N, indicating that any number of connectors 114 areincluded in the present invention, with each connector 114 having anynumber pins. Each pin can be interfaced with one dedicated interfaceapparatus 97. Each interface apparatus has one or more selectableinterconnection apparatus, such as interconnection apparatus 98-112. Themodule 66 therefore as shown provides interconnection apparatus 98-112for each of a plurality of lines 94 connector pins. Each set ofinterconnection apparatus 98-112 is dedicated for making a connection toone line 94 to one pin of one connector 114. The present inventiontherefore includes an interface apparatus including a set ofinterconnection apparatus such as 98-112 and corresponding requiredprogrammed logic in the microprocessor 82 for each line 94 leading toeach one of the connector pins of connectors 114, the pins for exampleas indicated by the circles on connector 114, for making connectionthrough a cable 68 to any corresponding device 70.

As an example of operation of the system 65, the microprocessor may beprogrammed to recognize particular input data, included for example inan Ethernet packet on line 86 containing instruction to transmit thedata as an analog signal on a particular on line 94 to a particulardevice 70. The programming in this case would instruct themicroprocessor to direct/convert the data through apparatus 98 having adigital to analog converter 116. Facility for making this connection issymbolized by relay “R1” which would be activated to make the requiredconnection from the device 116 to the device 70. As another example, ifline 94 were to carry 15 volts to the device 70, the microprocessorwould be Programmed to respond to a signal from the controller toactivate relay R6. In this manner, the system 65 allows communication ofa selected variety through any line such as 94, and application of anyone of a variety of signals to be sent to any selected line such as 94and thence to a corresponding device 70. The cable connecting to thelines such as line 94 can therefor be any cable capable of transmissionof the required signals, which as explained above is preferably aconventionally standard cable.

The circuit switching apparatus (R1-R8) are shown diagrammatically aselectromechanical relays. In one embodiment, this switching apparatus isrealized in a semiconductor circuit. A semiconductor circuit can berealized far less expensively and can act faster than anelectromechanical relay circuit. An electromechanical relay is used inorder to show the essence of the invention.

As shown in FIG. 6, any one of the eight signal path interconnectionapparatus indicated as 98-112 can be interconnected to line 94. FIG. 6shows, for example, apparatus for supplying four different power supplysignals for operational power to a particular pin including 24V DC,ground, 15V DC and −15V DC. The present invention also includes anyquantity or value of signals. Interconnection apparatus 102 provides fora digital signal to the pin connection to line 94. Interconnectionapparatus 108 provides a power supply return/ground. Interconnectionapparatus 98 and 100 provide digital-to-analog conversion, andanalog-to-digital conversion respectively. The directing apparatusmicroprocessor 82 is programmable to direct the module 66 to output afirst signal to the controller wherein the first signal conveys datacontent of a signal input from a device 70 to the module 66 to aselected one of the pins 117 of the connector 114. As described above,the module 66 is configured with a set of interconnection apparatus suchas 98-112 for each line 94 (FIG. 6) in each cable 68 (FIG. 5).

The lines and interconnections can carry any signal type. For example,signals can contain frequency information such as that found in feedbackfrom servo motors. Or these signals can represent serial communicationcarriers handling, for example, RS-232 data or fieldbus data such asDevice Net, Profibus or Ethernet.

FIG. 6 also illustrates the facility for connection of four non-powersignals by interconnection apparatus 98-104. Interconnection apparatus98 and 100 include A/D and D/A converters, as well as switchingapparatus (RI and R2), for situations where such conversion is necessaryto accommodate different transmission and receptioncapabilities/requirements of the controller 72 and a device 70.Interconnection apparatus 102 and 104 provide for passage of digitalsignals in either direction. In further explanation, the controller candirect the module 66 to send a digital signal, which when received bythe module 66, can be sent to a buffer 118, from which themicroprocessor 82 in response to direction from the controller can sendthe signal to any one of the contacts on connector 114 by activating therequired relay, such as interconnection apparatus 104 to connector 114,to send the required signal to the desired contact of the desiredconnector. Again, the routing of the signals is symbolically illustratedas accomplished by closing the associated relay (R1-R8). In the case ofthe aforementioned digital output signal, as shown in FIG. 6, relay R4would be closed, but relays R1-R3 and R5-R8 would be opened, thusrouting the requested digital output to line 94 and the correspondingpin of the standard I/O connector 114. Similarly, the module 66 canreceive a digital signal from a device 72, such as device 96, and inresponse to direction from the controller can send a copy to thecontroller 72. In this case, relay R3 would be closed, while relaysR1-R2 and R4-R8 would be opened, thus routing the digital signal fromthe given pin of the standard I/O connector 114 through interconnectionapparatus 102. Interconnection apparatus 98 and 100 accommodate analogto digital conversion as required. Finally, the configurable I/O system65 can be isolated from a signal such that the signal appears to bedisconnected. This disconnection is achieved by opening all relays,R1-R8.

Referring again to FIG. 5, a preferred method of the present inventionincludes the use of the system 65 in a control system wherein acontroller 72 receives data from or sends data to one or more devices 70through an I/O module 66 that is programmed to receive signals from andplace signals on any selected conductor of a selected cable to a device70. In a preferred embodiment, the device 72 is a system controller incommunication with the I/O module 66 through an Ethernet system 78.Alternatively, the device 72 can be of other configuration, such as ageneral purpose computer, and the communications line 78 can be of anytype, such as a standard computer cable, etc.

A further method of the present invention includes the use of the module66 for testing cables. FIG. 7 shows a first I/O module 120, connected toa second I/O module 122 with a cable 124 to be tested. According to apreferred embodiment, a system controller 126 is programmed to directmodule 120 to place a particular signal on a selected one of wires 128in cable 124. The signal can be for example, a DC supply voltage orother signal type as required for testing the cable 124. The controllerdirects the second module 122 to scan the pins 130 of the second module122. The results of the scanning are sent to the controller 126, wherebythe controller can know if the correct signal is on the correct pin todetermine the condition of the cable. In addition to determining thequality of transmission through a single selected cable conductor, thecontroller can scan and detect a signal on any pin 130 of the connectorof module 122, and therefore can determine if any of the conductors 128are shorted to each other, and can determine the level of cross talkbetween the conductors 128. FIG. 7 shows dashed lines 132 and 134representing communication lines between the system controller 126 andthe Modules 120 and 122.

A still further embodiment of the present invention includes a methodwherein a module configured to include the features of module 66 iscombined with an interlock for providing a safety feature in a system.FIG. 8 illustrates a prior art interlock system for protecting use of agas valve 134. Three relays 136, 138 and 140 must conduct current from a24VDC supply 142 in order for the gas valve 134 to receive operatingpower. The electrical windings for operating the relays 136, 138 and 140are symbolized by the circles 142, 144 and 146. The power to eachwinding is controlled by the sensor units 148, 150 and 152. If any oneof the three sensor units is activated and therefore disconnects powerto the corresponding winding, the associated relay disconnects/opencircuits and shuts off power to the gas valve. The interlock circuit ofFIG. 8 is often built into a custom circuit board requiring customwiring.

An embodiment of a method of the present invention is illustrated inFIG. 9 wherein configurable connectorized I/O Modules 166, 168 and 170,such as module 66, are used to minimize or eliminate custom wiring in aninterlock system. The Modules 166, 168 and 170 may be similar oridentical to the module 66 of FIGS. 5 and 6 with connections to theinterlock Modules 180, 182 and 184. The interconnections indicated inFIG. 9 can all or in part be accommodated with standard connectors andcabling, with the specific direction/routing of signals accomplished byprogramming the configurable, connectorized I/O modules.

The exemplified system 154 of FIG. 9 includes a system controller 156for controlling an operation including a device 158 such as a mass flowcontrol, etc. The system 154 includes an interlock system that allowsoperation of the device 158 only if the state of all three safetysensors 160, 162 and 164 indicate that operation conditions areappropriate. The sensors can be of any type for the purpose. The threeexamples are a proximity switch 160, a safety interlock 162 and a limitswitch 164.

The system controller 156 is connected to each of the threeconfigurable, connectorized I/O Modules 166, 168 and 170 which providethe programmable flexibility as described above, to allow standardcables and connectors to be used throughout the system to make thevarious connections indicated. I/o Modules 166, 168 and 170 are shownoverlapping the interlock Modules 180, 182 and 184 indicating that theinterlock Modules 180, 182 and 184 plug into the I/O Modules 166, 168and 170. In the preferred embodiment, the interlock Modules 180, 182 and184 plug into connector 74 of an I/O module such as Module 66 of FIG. 5in place of a cable 68. The interlock Modules 180, 182 and 184 eachcontain a device connector 74 into which a cable 68 plugs forinterconnecting the devices 158-164. The interlock Modules 180, 182 and184 therefore reside between the I/O Modules 166, 168 and 170 and thedevices 158-164 to which they attach, including as shown by example inFIG. 9 a proximity switch 160, limit switch 164, and safety interlock162, and device 158.

The system controller 156 communicates with I/O Modules 166, 168 and170, and with the interlock processor 172 by way of a network, such asEthernet as indicated by lines 174. Apparatus for accomplishing Ethernetcommunication will be understood to those skilled in the art, and thisneed not be illustrated in order to reproduce the invention. A powersupply 176 is shown with the connections symbolized by lines 178. Aninterlock module (180, 182, 184) is attached to each of the 1/0 modules(166, 168, 170). Each interlock module (180- 184) is attached to theinterlock processor 172 through cables/buses as indicated by lines 186,188 and 190.

The interlock system of FIG. 9 will not be explained in further detail.In general, the system 154 includes interlock modules (180, 182, 184)connected to an interlock processor 172 via bus lines (186, 188, 190).The Interlock Modules have two functions: (1) The first function, of theInterlock Modules 180 and 182, is to transmit the state of certaininputs, for example 192, 194 and 195 from sensors 160, 162 and 164, suchinputs being a subset of all inputs and being called Interlock Inputs,to the Interlock Processor 172 via the Interlock Buses 186 and 188. Anyinput (192, 194, 195) connected to any interlock module (180-184) can bewired within the interlock module such that the input drives a relaycoil, as shown in FIG. 8, with relay coils labeled (142, 144, 146). Whenthese relay coils are actuated, the associated relay contacts close.These relay coils each activate a contact resulting in a signal beingsensed by or sent to the Interlock processor 172 via the interlock buses186 and 188 to the Interlock Processor 172. The function of theInterlock Processor will be described shortly. (2) The second function,of the Interlock Module 184, is to receive one or more interlock signalsfrom the Interlock Processor 172 via the Interlock bus 190. TheInterlock Processor is wired such that the interlock signal or signalsthat the processor sends on the bus 190 drives a coil of a relay locatedin the Interlock module 184 whose contacts are in series with an outputof the I/O module 170. This output 197 is therefore interlocked. Thatis, the I/O module 170 can attempt to turn on an output connected to thedevice 158, but that output 197 will be prevented from progressingoutside the Interlock Module 184 (that is, interlocked) unless theInterlock Processor 172 drives a signal on the Interlock bus 190 whichcloses a relay in series with the output 197. The Interlock Processor172 is responsive to inputs from the Interlock Modules 180 and 182 byperforming Boolean logic upon the inputs to generate one or moreinterlock outputs on bus 190 that are routed to the Interlock Module 184and thereby interlock output 197 from the I/O Module 170. The InterlockProcessor 172 preferably does all of its processing using relays. Relaysare common in safety circuits since they are simple and reliable.Silicon switches and microprocessors have the reputation for being lessreliable and prone to various hardware or software glitches.Nonetheless, nothing in this application precludes the use of siliconprocessors, switches or logic. The cables 186, 188 and 190 are shownmaking direct connection between each interlock module and the interlockprocessor.

In operation, the proximity switch 160 provides an interlock input 192that is connected directly to the first interlock module 180. The safetyinterlock 162 provides a similar input 194. These two interlock inputs192 and 194 are sensed by the system controller 156 by way of connectionbetween the interlock module 180 and the I/O module 166, and inputmonitoring communications between the I/O module 166 and systemcontroller 156 by way of network 174. The interlock module 180 containsone relay for each interlock input 192 and 194. These relays (not shown)are for driving a signal via the Interlock Bus 186 to the InterlockProcessor 172. The Interlock Processor 172 contains one relay for eachinterlock input 192 and 194. The relays are arranged within theInterlock Processor 172 to perform a Boolean operation on the Interlocks160, 162, 164 and generate an interlock output that is routed via theInterlock Bus 190 to the Interlock Module 184. Inside the InterlockModule 184 is one relay (not shown) for each output such as output 197to be interlocked. In other words, although only one output 197 to onedevice 158 is shown in FIG. 9, the concept of the present inventionapplies to any number of inputs, outputs and devices. When the InterlockProcessor 172 determines that the Interlock inputs 160, 162, 164 are intheir correct states for proper system operation, the InterlockProcessor 172 drives a signal via the Interlock bus 190 and causes therelay in the Interlock Module 184 to close, thus allowing an output online 197 and therefore the device 158 to be enabled or turned on.

Referring now to FIG. 10 of the drawing, another embodiment of thepresent invention is illustrated wherein the interface apparatusincluding interconnection apparatus such as 98-112 illustrated in FIG. 6is configured as an application specific integrated circuit (ASIC) 198.The ASIC 198 is repeated within the I/O module 200 for each pin of eachconnector 202. For example, a series of ASICs 198 for the pins on oneconnector 202 are indicated by those enclosed by dashed line 204. Thus,if the connector 202 has 25 pins, then 25 ASICs 198 would be employedfor that one connector. The module 200 can contain any number of ASICs198, just as any module may contain any number of connectors 202.Another embodiment may employ a different ASIC architecture in whichmultiple pins are handled in each ASIC or multiple ASICs are used tohandle one or more pins. The result of using an ASIC is a dramaticreduction in the size and cost of building a module 200 by virtue of theminiaturization afforded by modern semiconductor processes. Again, thecircuit 200 of FIG. 10 is functionally similar or the same as thatcircuit module 66 described in reference to FIG. 6. The difference isthat the circuitry providing the function of interconnection apparatus98-112 or any combination of the elements 98-112 or other elements forinterfacing/communication with a pin, are incorporated in an ASIC 198 inthe circuit 200 of FIG. 10.

FIG. 11 depicts a block diagram of a pin driver ASIC 198. When connectedto the microprocessor 82 by a serial communication bus 206 such as anSPI interface, the microprocessor 82 of FIG. 10 can command the ASIC toperform the functions of the circuits of FIG. 6 shown as 98-112.Although the circuitry. of FIG. 11 appears different from theinterconnection apparatus 98-112 of FIG. 6, the circuit 198 is capableof performing the same or similar required functions. Whereas FIG. 6 isa somewhat idealized diagram intended to convey the essence of theinvention, FIG. 11 contains more of the circuit elements that one wouldplace inside an ASIC. Nonetheless, FIG. 11 implements all the circuitelements of FIG. 6. For example, FIG. 6. uses switch 98 to connect adigital-to-analog converter (D/A or DAC) to the output line 94A. In FIG.11, the digital-to-analog converter 226 is connected to the output pin208 via the switch 220. The present invention also includes othercircuit arrangements for an ASIC 198 for the same or similar purpose.Those skilled in the art will know how to design various such circuitry,and these are to be included in the present invention.

Exemplary features of the circuit of FIG. 11 will now be brieflydescribed. Power may be applied to pin 208 by closing high currentswitch 222 b and setting the supply selector 227 to any of the availablepower supply voltages such as 24-volts, 12-volts, 5-volts, ground ornegative 12-volts.

The circuit can measure the voltage on pin 208 by closing the lowcurrent switch 222 and reading the voltage converted by theanalog-to-digital converter 216.

The circuit can direct connect a thermocouple temperature sensorconnected at point/pin 208, wherein the sensor produces a very lowvoltage signal. A cross-point switch 210 allows a precision differentialamplifier 212 to connect to both leads of the thermocouple, one lead ofthe thermocouple being connected to the node/pin 208 connected to a pinof a connector 202 (FIG. 10), and the second lead of the thermocoupleconnected to another pin of the connector 202, which is connected to a4-way cross-point I/O 214 connector. The cross-point switch 210therefore allows two adjacent pins of a connector 202 to be connected tothe same analog-to-digital converter 216 via a differential amplifier212.

Circuit 198 has the ability to measure the amount of current flowing inor out of the node 208 labeled pin of FIG. 11. The pin driver circuit198 in this case uses its A/D converter 216 to measure current flowinginto or out of the pin node 208, thereby enabling the detection ofexcessive current, or detecting whether a device connected to the pinnode 208 is functioning or wired correctly.

ASIC 198 also has the ability to monitor the current flow into and outof the pin node 208 to unilaterally disconnect the circuit 198, therebyprotecting the ASIC 198 from damage from short circuits or otherpotentially damaging conditions. The ASIC 198 employs a so-called abusedetect circuit 218 to monitor rapid changes in current that couldpotentially damage the ASIC 198. Low current switches 220, 221 and 222and high current switch 222 b respond to the abuse detect circuit 218 todisconnect the pin 208.

The ASIC 198 abuse detect circuit 218 has the ability to establish acurrent limit for the pin 208, the current limit being programmaticallyset by the microprocessor 82. This is indicated by selections 224.

The ASIC 198 can measure the voltage at the pin node 208 in order toallow the microprocessor 82 to determine the state of a digital inputconnected to the pin node. The threshold of a digital input can therebybe programmed rather than being fixed in hardware. The threshold of thedigital input is set by the microprocessor 82 using thedigital-to-analog converter 226. The output of the digital-to-analogconverter 226 is applied to one side of a latching comparator 225. Theother input to the latching comparator 225 is routed from the pin 208and represents the digital input. Therefore, when the voltage of thedigital input on the pin 208 crosses the threshold set by thedigital-to-analog converter, the microprocessor 82 is able to determinethe change of the input and thus deduce that the digital input haschanged state.

The ASIC 198 can receive or produce frequency signals. If a serialcommunication device, for example a printer, is connected to pin 208,then said frequency signals can be routed through the low current switch221 and thence to a universal asynchronous receiver transmitter (UART)or similar circuit element (not shown) that can interpret the frequencyinformation. All of the ASICs 198 in a module 66 can route the frequencyinformation to one of four wires that make up the frequency bus 230. Byemploying said frequency bus 230, it is possible for the module 66 toreceive and transmit frequency signals configured as either single-endedor differential. Such serial electrical standards as RS-422 provide fordifferential serial information.

The ASIC can produce a current source at the pin node, the currentsource being a standard method of connecting various industrial controldevices. The ASIC can produce signals varying over the standard 4-20 mAand 0-20 mA range. This current source means is accomplished by themicroprocessor 82 as it causes the digital-to-analog converter 226 toproduce a voltage which is routed to the Selectable Gain Voltage Bufferor Current Driver 231 and then through the selectable source resistor227, said selectable source resistor 227 being set to the appropriateresistance by the microprocessor 82 to achieve the desired outputcurrent. The current is regulated by the Selectable Gain Voltage Bufferor Current Driver 231 using feedback through the analog switch 229 usingpath A.

The ASIC can measure a current signal presented at the pin node, thecurrent signal being produced by various industrial control devices. TheASIC can measure signals varying over the standard 4-20 mA and 0-20 mArange. This current measurement means is accomplished by themicroprocessor 82 as it causes the selectable gain voltage buffer 231 toproduce a convenient voltage such as zero volts at its output terminal.At the same time, the microprocessor 82 causes the selectable sourceresistor 228 to present a resistance to the path of current from theindustrial control device and its current output. Said current entersthe ASIC 198 via the pin 208. The imposed voltage on one side of a knownresistance will cause the unknown current from the external device toproduce a voltage on the pin 208 which is then measured via theanalog-to-digital converter 216 through the low current switch 222. Themicroprocessor 82 uses Ohm's Law to solve for the unknown current beinggenerated by the industrial control device.

Other enhancements of the present invention include the ability of themodule 200 to perform independent control of devices connected to themodule 200. If, for example, a thermocouple or other temperature sensoris connected to the module 200 along with a heater, then themicroprocessor 82 can read the temperature sensor, and activate theheater in such a manner that a desired temperature is achieved. Saidheater usually employs an amplifier (for example a relay) which convertsthe low-level output of the module 200 into a high-power output capableof driving a heater. The module 200 can thereby perform closed loopcontrol. In such as case, said thermocouple would be connected to twoadjacent pins 208 configured as inputs, while said heater would beconnected to two pins 208, said heater pins being configured as outputs.In operation, the microprocessor 82 would measure the voltage of thetemperature sensor as described above. The microprocessor 82 would applythe desired temperature using known control algorithms to the measuredtemperature and develop an actuation signal also using the acceptedmethods. The microprocessor would then actuate the heater either with acontinuously variable analog signal or via a pulse width modulated (PWM)on/off signal. Thus, independent control of devices connected to themodule 200 is achieved.

The ASIC 198 includes functions as described above in reference to theinterface apparatus 97. For example, an ASIC 198 has an interconnectionapparatus having a digital-to-analog converter, 226, and wherein thedirecting apparatus is programmable to direct the reception of a digitalsignal from the microprocessor 82 and cause the signal to be convertedby the digital-to-analog converter 226 to an analog signal, and to placea copy of the analog signal on the pin 208.

The ASIC 198 can also include an interconnection apparatus including ananalog-to-digital converter 216, and wherein the directing apparatus isprogrammable to detect an analog signal on any selected contact of thefirst connector apparatus and cause the analog-to-digital converter 216to convert the signal to a digital signal and output a copy of thedigital signal to the microprocessor 82.

The ASIC 198 can also include directing apparatus, called a supplyselector 227, and then routed through the high current switch 222 b tothe pin 208. Said directing apparatus is programmable to cause a powersupply voltage to be connected to a first selected connector pin node ofthe first connector apparatus, and to cause a power supply return to beconnected to a second selected pin of the first connector apparatus.

While a particular embodiment of the present invention has been shownand described, it will be obvious to those skilled in the art thatchanges and modifications may be made without departing from the spiritof the present invention, and therefore the appended claims are toinclude these changes and alterations as follow within the true spiritand scope of the present invention.

1. A configurable connectorized system comprising: (a) a moduleincluding (i) a device communication connector apparatus including aconnector for connecting a cable between said module and a device; and(ii) directing apparatus programmable by a user of said system andresponsive to an input signal from a controller apparatus for causingsaid module to place any of a plurality of signals on any of a pluralityof connector pins of said connector, wherein said directing apparatusincludes at least one ASIC providing a selectable interconnectionapparatus to a particular one of said connector pins. 2-19. (canceled)